I have a Sharp SPC373 Atomic clock every 2 years the batteries die and I can never find the manual when I need it. When I google this topic I just find people looking for the Manual. So google here is your answer. I dug up my manual and will paraphrase the most common stuff here.
Remote Temperature: Important note install the batteries in the remote sensor first, before you install batteries in the clock. if the sensor will not detect you need to manually search for the sensor. Make sure the channel settings are correct on the remote sensor and the clock (Default Ch1) Press and hold the Test Button, the channel display will blink. If you still cant get it to work try it in the same room. If it still wont work. Press The reset button on the clock and sensor then try again. If it still wont work buy a new clock.
Set the Time Zone: press Time button once to view current zone, pressup or down to change the zone, press the Time Button to exit the setting mode.
Set Time and Date: press the Time or Month/Day button for 3 secondsto set. use up and down to change value
Radio Control Time:Once the batteries are installed in the clockthe clock will begin to seek out the signal to update the time this will take 5–8minutes if 8 minutes has gone by recommend setting time manually. Otherwise you canpress the Receive button to tell the clock to seek the NIST WWVB signal. The clockwill only search for signal at night automatically @17:00 and 02:00. If the radio icon is flashing in the clock area the signal is received ok, if noneor part of the icon is showing the signal is poor or not working correctly (the iconis a satalight looking thing with 5 ‘radials’ that blip towards the mainicon), relocate your clock or try later. It is recommend to set the clock manuallythen let the automatic control take over.
the 12/24 button will set ‘military time’ the Min/Max button will showthe current min or max temp on record for the sensors. The Alert button is for settinga alarm to the temperature sensors, note that the time alarm must also be on for thetemperature alarm to activate.
if something is not clear I can re-phrase from the original guide or fix it here,just comment or email.